LED optical lens is closely linked with the LED to enhance the efficiency of light use and luminous efficiency, according to different effects to use different lenses. According to the different materials, we can be generally divided into four categories.

One is the silica gel lens, because silica gel high temperature resistance (also can be reflow soldering), so often used directly encapsulated LED light-emitting devices. One is the PMMA lens, the optical grade PMMA (polymethyl methacrylate, commonly known as acrylic). Plastic materials, advantages: high production efficiency, high transmittance (3mm thickness when the penetration rate of around 93%);

Disadvantages: large volume, heavy weight, single shape, fragile, batch production is not easy to achieve, low production efficiency, high cost. The price of this kind of production equipment is high and it is difficult to popularize in the short term. In addition, the glass is more fragile than PMMA and PC materials, but more research and exploration are needed. The improved technology can only be achieved by coating or tempering to enhance the glass's non-fragile characteristics. Although after these treatments, the transmittance of the glass lens will be reduced, but still far greater than ordinary optical plastics. The translucent effect of lens. So the prospect of glass lenses will be broader.